Rivian has not released any info/specs about the sound system other than saying (I believe in a YT video I saw) that it would be a premium system. FWIW, there's a YT video that highlights the infotainment within the dash displays.
Yeah, they did say premium at the Flagstaff event and referenced Audi in some video's I watched as a comparison. I always am leery about truck audio systems and they're speaker arrangement. A great (not just good) sound system is crucial for EV's with they're near silent operation. I'd be hoping for like at least a 12 speaker set up, with 2 speakers per door, 1 for each a-post, a center channel speaker and sub under the seats. But again the more the better.
